In so-called direct synthesis, a process in which silicon powder is reacted with methyl chloride in the presence of a copper catalyst, further silanes, such as dimethylchlorosilane, but only in low yields, are also obtained in addition to the main product dimethyldichlorosilane.
According to U.S. Pat. No. 3,399,222, for redistribution of dimethyldichlorosilane with methyldichlorosilane in the presence of quaternary ammonium salts, the following equilibrium lies on the lefthand side: EQU (CH.sub.3).sub.2 SiCl.sub.2 +CH.sub.3 HSiCl.sub.2 .revreaction.(CH.sub.3).sub.2 HSiCl+CH.sub.3 SiCl.sub.3
U.S. Pat. No. 4,870,200 describes the disproportionation of methyldichlorosilane to give methylchlorosilane and/or methylsilane in the presence of a catalyst comprising a support which is insoluble in the reaction medium and on which tertiary amine groups or quaternary ammonium groups are covalently bonded.
U.S. Pat. No. 5,252,768 describes a process for the preparation of dimethylchlorosilane by redistribution of dimethyldichlorosilane with methylchlorosilane an/or methylsilane in the presence of a catalyst comprising a support which is insoluble in the reaction medium and on which tertiary amine groups or quaternary ammonium groups are covalently bonded.
U.S. Pat. Nos. 4,410,669 and 5,130,396 disclose shapeless and spherical polymeric, optionally crosslinked organosiloxane-ammonium compounds having a silica-type backbone, and their use as ion exchangers.
U.S. Pat. No. 5,094,831 describes a process for the dismutation of chlorosilane, in which these are passed in gaseous or liquid form over a catalyst which is shapeless or in the form of spheres and comprises one of four different optionally crosslinked organopolysiloxane compounds essentially carrying an amino or ammonium grouping as the functional group.